Michael Tsai, writing on the latest issue that hit the Mac App Store, preventing users to launch apps they previously downloaded:

I woke up to an inbox full of e-mails from customers reporting that my apps wouldn’t launch. This included new customers who had just purchased from the Mac App Store as well as people who had purchased long ago, hadn’t made any changes, and expected that things would just keep working.

And:

The Mac App Store is supposed to make things easier, but it’s also a single point of failure. Not only is it neglected, but sometimes even the existing functionality stops working. Mac OS X 10.9 introduced a code signing bug that prevented me from submitting updates for several months. In June 2015, there was a month-long iTunes Connect bug that prevented my uploaded build from entering the review queue. And I currently have a bug fix update that Apple has been reviewing for 33 days (with 8 days of waiting before that). When I inquired about the status, Apple told me that everything was normal and that I should just keep waiting. In short, the system is broken on multiple levels, and there is no evidence to suggest that things will get better.

This problem hit me as well – I had to check something on Tweetbot for Mac last night, but it wouldn’t launch. Same with other apps. There is a workaround, but it’s not working for everyone. And, despite the widespread nature of the problem, Apple has said nothing about it.

The Mac App Store lives in a sad state of abandon when compared to its iOS counterpart. For years now, Mac developers haven’t gotten access to the same tools made available to iOS developers. And that’s not to mention the myriad of issues and uncertainty they had to go through when Apple started rolling out sandboxing.

But preventing people from using apps they bought without a proper explanation, affecting third-party developers in the process? Just inexcusable.